Critical Angle Refractometry for Lossy Media with a Priori Known Extinction Coefficient

Critical angle refractometry is an established technique for determining the refractive index of liquids and solids. For transparent samples, the critical angle refractometry precision is limited by incidence angle resolution. For lossy samples, the precision is also affected by reflectance measurement error. In the present study, it is demonstarted that reflectance error can be practically eliminated, provided that the sample’s extinction coefficient is a priori known with sufficient accuracy (typically, better than 5%) through an independent measurement. Then, critical angle refractometry can be as precise with lossy media as with transparent ones.

Development and Initial Validation of a Scale Assessing Suicide-Specific Rumination: The Suicide Rumination Scale

Suicide-specific rumination, a repetitive mental fixation on one’s suicidal thoughts and intentions, may influence the transition from suicidal thoughts to behaviors. Research on suicide-specific rumination has been hindered by the lack of an independent measurement tool. This article presents the development and validation of a self-report measure of suicide-specific rumination across several samples with lifetime suicidal ideation (Sample 1: N = 494 students; Sample 2: N = 219 community members; Sample 3: N = 128 adults at high risk for suicide). The Suicide Rumination Scale (SRS) item pool was reduced from a pool of 41 items to 8 items that are highly discriminant and of varying levels of difficulty. The SRS demonstrated measurement invariance, convergent validity, and nonredundancy with related measures. Importantly, the SRS differentiated suicide attempters from ideators, suggesting its potential clinical relevance. Overall, these findings suggest that the SRS is a valid and incrementally useful measure of suicide-specific rumination.

EEG-based visual deviance detection in freely behaving mice

The mouse is widely used as an experimental model to study visual processing. To probe how the visual system detects changes in the environment, functional paradigms in freely behaving mice are strongly needed. We developed and validated the first EEG-based method to investigate visual deviance detection in freely behaving mice. Mice with EEG implants were exposed to a visual deviant detection paradigm that involved changes in light intensity as standard and deviant stimuli. By subtracting the standard from the deviant evoked waveform, deviant detection was evident as bi-phasic negativity (starting around 70 ms) in the difference waveform. Additionally, deviance-associated evoked (beta/gamma) and induced (gamma) oscillatory responses were found. We showed that the results were stimulus independent by applying a 'flip-flop' design and the results showed good repeatability in an independent measurement. Together, we put forward a validated, easy-to-use paradigm to measure visual deviance processing in freely behaving mice.

Connecting gravity field, moment of inertia, and core properties in Jupiter through empirical structure models

<p>Constraining Jupiter's internal structure is crucial for understanding its formation and evolution history. Recent interior models of Jupiter that fit Juno's measured gravitational field suggest an inhomogeneous interior and potentially the existence of a diluted core. These models, however, strongly depend on the model assumptions and the equations of state used. A complementary modelling approach is to use empirical structure models. <br>These can later be used to reveal new insights on the planetary interior and be compared to standard models. <br>Here we present empirical structure models of Jupiter where the density profile is constructed by piecewise-polytropic equations. With these models we investigate the relation between the normalized moment of inertia (MoI) and the gravitational moments J<sub>2</sub> and J<sub>4</sub>. <br>Given that only the first few gravitational moments of Jupiter are measured with high precision, we show that an accurate and independent measurement of the MoI value could be used to further constrain Jupiter's interior. An independent measurement of the MoI with an accuracy better than ~0.1% could constrain Jupiter's core region and density discontinuities in its envelope. <br>We find that models with a density discontinuity at ~1 Mbar, as would produce a presumed hydrogen-helium separation, correspond to a fuzzy core in Jupiter. <br>We next test the appropriateness of using polytropes, by comparing them with empirical models based on polynomials. <br>We conclude that both representations result in similar density profiles and ranges of values for quantities like core mass and MoI.</p>

Satellite-based estimates of decline and rebound in China’s CO2 emissions during COVID-19 pandemic

Changes in CO2 emissions during the COVID-19 pandemic have been estimated from indicators on activities like transportation and electricity generation. Here, we instead use satellite observations together with bottom-up information to track the daily dynamics of CO2 emissions during the pandemic. Unlike activity data, our observation-based analysis deploys independent measurement of pollutant concentrations in the atmosphere to correct misrepresentation in the bottom-up data and can provide more detailed insights into spatially explicit changes. Specifically, we use TROPOMI observations of NO2 to deduce 10-day moving averages of NOx and CO2 emissions over China, differentiating emissions by sector and province. Between January and April 2020, China’s CO2 emissions fell by 11.5% compared to the same period in 2019, but emissions have since rebounded to pre-pandemic levels before the coronavirus outbreak at the beginning of January 2020 owing to the fast economic recovery in provinces where industrial activity is concentrated.